Describing himself as a non-smoking teetotaller, he also accused some colleagues of hypocrisy for wanting to ban smoking because “nice people” did not do it while being relaxed about alcohol, because they themselves drink, despite so many children’s lives being blighted by alcoholic parents.”

But Labour Shadow health minister Luciana Berger said the ban was widely backed by doctors and the public and claimed the legislation would help protect children from the dangers of second-hand smoke.

She added: “This is a great victory for child health which will benefit hundreds of thousands of young people. It is a matter of child protection, not adult choice.

“Minsters now have a duty to bring forward regulations so that we can make this measure a reality and put protections for children in place as soon as possible.”